Rotating method

ABSTRACT

The invention relates to a rotatable lead-through for connection of a coolant feed to a roller, especially for continuous casting plants, which roller is mounted by way of journals in bearing blocks in rolling bearings and which is supplied with the coolant by way of axial bores through the journals, said rotatable lead-through having a flange with an elastic sleeve pressure-tightly fixed thereon, a first sealing element fixed on said elastic sleeve and rotating therewith and having a first sealing surface, a second sealing element having a second sealing surface running on said first sealing surface and being supported by or integrated into a bearing block cover fixed on the bearing block for covering the roller bore and the roller bearings, and an axial bore penetrating said elastic sleeve and said bearing block cover and permitting the feeding of coolant into the interior of the roller, wherein the sealing surfaces of the sealing elements are perpendicular to the rotation axis.

[0001] The present invention relates to a rotatable lead-through having the features according to the preamble to claim 1.

[0002] Rotatable lead-throughs are required in different branches of industry, especially for continuous casting plants in the steel industry. In these continuous casting plants, the red-hot steel runs in the form of billets over rollers, which are. rotatably mounted externally in bearings in bearing blocks. These rollers are cooled in a closed circulation by admission of water under pressure into the interior of the rollers to dissipate heat. The rotatable lead-through seals the transition from the so-called rotor and the cooling water line flange-mounted thereon to the housing secured to the roller and co-rotating with it.

[0003] Essentially two different types of rotatable lead-through are known in the art. A first construction of the rotatable lead-throughs comprises a structural unit lying outside the roller interior, which contains the elements for the necessary water supply, mounting and sealing. Depending on the construction, installations of that kind having such rotatable lead-throughs have a considerable width to the right and left of the bearing blocks.

[0004] To reduce the installation width, the system manufacturers have been required to move the bearing and sealing system to the inside of the roller.

[0005] To receive the rotatable lead-through in the roller, a bore is provided, into which the rotatable lead-through is inserted and then fixedly connected, for example, by way of a screwed connection, to the roller. The water used for cooling is introduced into the rotatable lead-through at an excess pressure of up to 15 atmospheres, and the water pressure acting on the components together with the movement of the same and the thermal stress, places heavy demands on the sealing technology.

[0006] A technique used to seal the components of the rotatable lead-through moving relative to one another as the roller rotates is based on the use of a radial seal consisting of circular O-rings or lip seals of elastomer as the crucial sealing element.

[0007] Other techniques are described in EP-A1-392 838. This publication describes a rotatable lead-through with a sealing arrangement that is operated by the hydraulic pressure of the fluid. This is, however, a structurally complex arrangement.

[0008] An attribute common to the rotatable lead-throughs known in the art is that, especially when the roller is subjected to radial loadings, because of the relatively rigid water supply and discharge lines, shearing forces act on the rotatable lead-throughs and cause considerable wear to the rotatable lead-through. An added factor is the mostly complicated mechanical construction of the rotatable lead-throughs known in the art.

[0009] It is therefore an object of the present invention to provide a wear-resistant lead-through, which permits a reliable operation combined with an extended service life, is of simple construction and in the case of continuous casting installations currently in use can be used as exchangeable component without modification to the installation itself.

[0010] The problem of the invention is solved by providing a rotatable lead-through for connection of a coolant feed to a roller, especially for continuous casting plants, which roller is mounted by way of journals in bearing blocks in rolling bearings and which is supplied with the coolant by way of axial bores through the journals, said rotatable lead-through having a flange 2 with an elastic sleeve 1 pressure-tightly fixed thereon, a first sealing element 7 fixed on said elastic sleeve 1 and rotating therewith and having a first sealing surface, a second sealing element 8 having a second sealing surface running on said first sealing surface and being supported by or integrated into a bearing block cover 20 fixed on the bearing block for covering the roller bore and the roller bearings, and an axial bore penetrating said elastic sleeve and said bearing block cover and permitting the feeding of coolant into the interior of the roller, wherein the sealing surfaces of the sealing elements 7, 8 are perpendicular to the rotation axis.

[0011] The rotatable lead-through according to the present invention has the advantages that it is of simple construction, has an increased resistance to wear and a reduced susceptibility to failure, thus enabling an extended service life to be achieved. The components used can easily be exchanged when worn.

[0012] The rotatable lead-through according to the present invention comprises, as one component group of the rotatable lead-through, the flange unit consisting of flange with pressure-tightly fixed sleeve thereon, a first sealing element fixed on said elastic sleeve and rotating therewith and having a first sealing surface, wherein a second component group comprises the bearing block cover with the second sealing element having the second sealing surface running on said first sealing surface.

[0013] The bearing block cover is fixed, preferably screwed on said bearing block of the roller, and therefore covers/closes the roller bearings and the roller bore, thereby protecting the rotatable lead-through fitted therein against dirt accumulation and wear.

[0014] According to a preferred embodiment a pressure plate is pressure-tightly fixed into said bearing block cover, which supports said second sealing element. Further, the pressure plate is preferably arranged, optionally resiliently supported, to be movable in the radial direction, so that an improved bearing for the pressure plate is achieved.

[0015] Due to the embodiment of the sealing surfaces of the sealing elements running on each other perpendicular to the rotation axis, an enhanced axial mobility of the sealing elements of the rotatable lead-through is achieved, leading to a reduced wear on load.

[0016] Although the sealing elements may be formed by providing plan surfaces, running on each other, on the sleeve head and the bearing block cover, the use of. at least one sliding ring being integrated in one of said planar surfaces as sealing element is preferred, wherein said sealing ring usually consists of silicon carbide, carbon graphite or similar materials. In case of using two sliding rings, one of these sliding rings is fixedly anchored in the stationary component, the complementary planar surface of the other sliding ring, as rotary counter-ring, being able to run on the planar surface of said first sliding ring.

[0017] An example of the present invention is illustrated in the single FIG. 1.

[0018] As shown in FIG. 1, the rotatable lead-through according to the present invention comprises as components the flange 2 with the elastic sleeve 1 fixed thereon, the sliding ring positioned on the side opposite to the sleeve 1 as sealing element 7 and corresponding thereto the sealing ring as sealing element 8 on the pressure plate 4, wherein said pressure plate 4 is positioned beyond the housing 3 in the cover of the rotatable lead-through. The pressure plate 4 may be locked against rotation by means of dowel pins and may be sealed against the housing 1 by means of the O-ring 14. A falling-out of the pressure plate may be avoided by pressing the pressure plate into the cover for covering the roller bore.

[0019] The sliding rings 7, 8 may be formed from a material known in the prior art, however the use of silicon carbide or electro carbon graphite is preferred because of their wear resistance.

[0020] The O-rings used can be formed of materials which are common in the prior art, such as rubber, silicon rubber etc. In the embodiment shown in the FIGURE, the elastic sleeve, being realized as a compensator, is held under tension between the cover and the sleeve foot, or flange 2, respectively. Hereby, a pretension and a better sealing effect between the sealing surfaces is achieved.

[0021] In an embodiment not illustrated in the FIGURE, the elastic sleeve is formed in shape of a hollow rubber cylinder fitted between sleeve foot and sleeve head, if necessary reinforced by means of a fabric. In this embodiment, a particular flexibility of the sleeve is achieved and therefore the wear of the rotatable lead-through on load is further reduced.

[0022] In a preferred embodiment the elastic sleeve 1 may be removed from the flange. In this embodiment an exchange of the elastic sleeve 1 for adjusting a pretension adapted to the sealing conditions is possible, as well as an adaptation of the length of the sleeve to the corresponding distance between bearing block and bearing block cover. In this way, the construction length of the sleeve may easily be changed. In this case, the end of the sleeve 1 facing to the interior of the roller is removable fixed via the sleeve foot on the flange 2 be means of screws 19, and the sleeve foot is pressure sealed against the flange 2 by means of the O-ring 18.

[0023] The water-intake or -feed into the interior of the roller is realized by the siphon pipe with connection fitting 21 penetrating the rotatable lead-through, which is inserted from exterior through the cover 20 for covering the roller bore and fixed thereto on its outer side.

[0024] The rotatable lead-through according to the present invention may be easily disassembled into its components, so that a fast exchange of worn components is possible. 

1. A rotatable lead-through for connection of a coolant feed to a roller, especially for continuous casting plants, which roller is mounted by way of journals in bearing blocks in rolling bearings and which is supplied with the coolant by way of axial bores through the journals, said rotatable lead-through having a flange (2), arranged in said journal, with an elastic sleeve (1) pressure-tightly fixed on said flange (2), a first sealing element (7) fixed on said elastic sleeve (1) and rotating therewith and having a first sealing surface, a second sealing element (8) having a second sealing surface running on said first sealing surface and being supported by or integrated into a bearing block cover (20) fixed on said bearing block for covering the roller bore and the roller bearings, and an axial bore penetrating said elastic sleeve and said bearing block cover and permitting the feeding of coolant into the interior of the roller, wherein the sealing surfaces of the sealing elements (7, 8) are perpendicular to the rotation axis.
 2. A rotatable lead-through according to claim 1, wherein said second sealing element (8) is supported by a pressure plate (4) being pressure-tightly fitted into said bearing block cover (20), and wherein the axial bore penetrates said elastic sleeve (1) and said pressure plate (4).
 3. A rotatable lead-through according to claim 2, wherein said pressure plate (4) is arranged, optionally resiliently supported, to be movable in the radial direction.
 4. A rotatable lead-through according to anyone of the claims 1 to 3, wherein said elastic sleeve (1) is removable fixed on said flange (2).
 5. A rotatable lead-through according to anyone of the claims 1 to 4, characterized in that said elastic sleeve is a compensator.
 6. A rotatable lead-through according to anyone of the claims 1 to 5, characterized in that at least one of said first and second sealing elements (7, 8) is formed as a sliding ring.
 7. A rotatable lead-through according to claim 6, characterized in that said sliding ring consists of electro carbon graphite or silicon carbide. 